Conformal fluid-cooled heat exchanger for battery

ABSTRACT

A heat exchanger for use with at least two battery modules, each of the battery modules comprising at least one battery cell housed within a rigid container, the heat exchanger defining an internal fluid passage for a heat exchanger fluid and having at least one compliant region that is configured to be compressed to facilitate thermal contact between the heat exchanger and the two battery modules.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional application based on U.S. patentapplication Ser. No. 13/261,622 filed May 28, 2013 which claims thebenefit of and priority to U.S. Provisional Patent Application No.61/389,301 filed Oct. 4, 2010 under the title CONFORMAL FLUID-COOLEDHEAT EXCHANGER FOR BATTERY CELL STACK.

The content of the above patent applications are hereby expresslyincorporated by reference into the detailed description hereof.

BACKGROUND

This disclosure relates to heat exchangers used to dissipate heat inrechargeable batteries and other electricity producing cells.

Rechargeable batteries such as batteries made up of many lithium-ioncells can be used in many applications, including for example inelectric vehicle (“EV”) and hybrid electric vehicle (“HEV”) applicationsamong other things. Such batteries can generate large amounts of heatthat needs to be dissipated.

SUMMARY

According to an example embodiment of the present disclosure there isprovided a heat exchanger for use with at least two battery modules,each of the battery modules comprising at least one battery cell housedwithin a rigid container, the heat exchanger comprising:

a plurality of substantially rigid planar heat exchanger plates thateach include a main plate section defining an internal fluid passage andan inlet panel and an outlet panel that are joined to the main platesection and define an inlet fluid passage and an outlet fluid passage,respectively, that communicate with the internal fluid passage, each ofthe panels being compliantly joined to the main plate section such thatthe main plate section can be displaced relative to the panels, theinlet and outlet panels of at least some of the heat exchanger platesbeing joined to the inlet and outlet panels of adjacent heat exchangerplates to form a stack of spaced apart, substantially parallel, heatexchanger plates, the main plate sections being compressible together toengage battery modules inserted therebetween.

According to another example embodiment of the present disclosure thereis provided a heat exchanger for exchanging thermal energy with batterymodules, comprising:

a plurality of heat exchanger plates, each heat exchanger plate definingan internal fluid flow passageway for a heat exchanger fluid andarranged in a stack in which adjacent heat exchanger plates are spacedapart from each other, the adjacent heat exchanger plates eachincluding:

-   -   a main plate section;    -   an inlet panel defining an inlet fluid passage in fluid        communication with the internal fluid flow passageway; and    -   an outlet panel defining an outlet fluid passage in fluid        communication with the internal fluid flow passageway;        wherein the inlet and outlet panel are each compliantly joined        to the main plate section such that the main plate section can        be displaced relative to the inlet and outlet panels, the inlet        and outlet panels of one heat exchanger plate being joined,        respectively, to the inlet and outlet panels of at least one        adjacent heat exchanger plate to form a stack of spaced apart,        substantially parallel heat exchanger plates, the main plate        sections being movable relative to their respective inlet and        outlet panels at least prior to insertion of battery modules        between the heat exchanger plates.

According to another example embodiment of the present disclosure thereis provided a method of assembling a battery unit comprising:

providing a substantially rigid heat exchanger having at least onecompliant region, wherein providing the heat exchanger comprises:

providing a plurality of substantially rigid and planar heat exchangerplates that each include a main plate section defining an internal fluidpassage and an inlet panel and an outlet panel that are joined to themain plate section and define an inlet fluid passage and an outlet fluidpassage, respectively, that communicate with the internal fluid passage,each of the panels being compliantly joined to the main plate sectionsuch that the main plate section can be displaced relative to thepanels, andrigidly joining the inlet and outlet panels of at least some of the heatexchanger plates to the inlet and outlet panels of adjacent heatexchanger plates to form a stack of spaced apart, substantiallyparallel, heat exchanger plates; andproviding at least two battery modules, each of the battery modulescomprising at least one battery cell housed within a rigid container;andinserting a battery module between adjacent pairs of the heat exchangerplates such that the heat exchanger plates and battery modules areinterleaved; andcompressing the main plate sections together for contact with thebattery modules.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic perspective view of a battery unit according to anexample embodiment.

FIG. 2 is an enlarged front view illustrating part of three adjacentbattery cell containers of one of the battery modules of the batteryunit of FIG. 1.

FIG. 3 is a perspective view of a fluid-cooled heat exchanger accordingto an example embodiment.

FIG. 4 is a plan view of the heat exchanger of FIG. 3.

FIG. 5 is a sectional view of the heat exchanger taken across the linesV-V of FIG. 4.

FIG. 6 is an enlarged view of portion 6 of FIG. 5.

FIG. 7 is an exploded view of a flow chamber region of FIG. 6.

FIG. 8 is a perspective view of an inner core plate of the heatexchanger of FIG. 3.

FIG. 9 is a perspective view of an outer core plate of the heatexchanger of FIG. 3.

FIG. 10 is a plan view of a first closure plate of the heat exchanger ofFIG. 3.

FIG. 11 is a plan view of a second closure plate of the heat exchangerof FIG. 3.

FIG. 12 is a perspective view of a fluid-cooled heat exchanger accordingto another example embodiment.

FIG. 13 is a plan view of one side of the heat exchanger of FIG. 12.

FIG. 14 is a plan view of the opposite heat exchanger of FIG. 12.

FIG. 15 is a sectional view of the heat exchanger taken across the linesXV-XV of FIG. 14.

FIG. 16 is plan view of a first core plate of the heat exchanger of FIG.12.

FIG. 17 is a plan view of a second core plate of the heat exchanger ofFIG. 12.

FIG. 18 is a sectional view of the second core plate taken across thelines XVIII-XVIII of FIG. 17.

FIG. 19 is a plan view of a compliant plate of the heat exchanger ofFIG. 12.

FIG. 20 is a sectional view of the compliant plate taken across thelines XX-XX of FIG. 19.

FIG. 21 is an enlarged sectional view of part of a compliant platestructure of the heat exchanger of FIG. 12.

FIG. 22 is an end view of a battery unit according to a further exampleembodiment.

FIG. 23 is an enlarged sectional view taken along the lines A-A of FIG.22.

FIG. 24 is a perspective view of a battery module of the heat exchangerof FIG. 22.

FIG. 25 is a perspective view of part of the heat exchanger of FIG. 22.

FIG. 26 illustrates various compliant boss configurations that can beapplied to the heat exchanger of FIG. 22.

FIG. 27 is a partial perspective view of a further example embodiment ofa heat exchanger.

FIG. 28 is a partial perspective view of a plate of the heat exchangerof FIG. 27.

FIG. 29 is a top plan view of a battery unit that includes the heatexchanger of FIG. 27.

FIGS. 29A, 29B and 29C are top plan views of respective embodiments of aheat exchanger.

FIG. 30 is a sectional view of the battery unit of FIG. 29, taken alongthe lines XXX-XXX of FIG. 29.

FIG. 31 is a further sectional view of the battery unit of FIG. 30,taken along the lines XXXI-XXXI of FIG. 29.

FIGS. 32A and 32 B are each enlarged partial sectional views (taken froma similar view as FIG. 23) that illustrate further example embodiment ofa heat exchanger that includes manifold connectors between compliantboss regions of adjacent heat exchanger plates.

FIG. 33 is an enlarged partial sectional view (taken from a similar viewas FIG. 23) that illustrate further example embodiment of a heatexchanger that includes a two-piece compliant manifold connector betweenadjacent heat exchanger plates.

FIG. 34 is a schematic sectional view that further illustrates acompliant manifold connector of the heat exchanger of FIG. 33.

FIG. 35 is a front view of the compliant manifold connector of FIG. 34.

FIGS. 36A, 36B and 36C are views of a further embodiment of a two-piececompliant manifold connector that can be applied to the heat exchangerof FIG. 33, with FIG. 36A being a top view, FIG. 36B being a sectionalview taken along lines A-A of FIG. 36A and FIG. 36C being a perspectiveview.

FIG. 37 is a sectional view of a yet a further embodiment of a two-piececompliant manifold connector that can be applied to the heat exchangerof FIG. 33.

DESCRIPTION OF EXAMPLE EMBODIMENTS

Reference will now be made in detail to implementations of thetechnology. Each example is provided by way of explanation of thetechnology only, not as a limitation of the technology. It will beapparent to those skilled in the art that various modifications andvariations can be made in the present technology. For instance, featuresdescribed as part of one implementation of the technology can be used onanother implementation to yield a still further implementation. Thus, itis intended that the present technology cover such modifications andvariations that come within the scope of the technology.

FIG. 1 shows an illustrative example of a rechargeable battery unit 100according to example embodiments of the invention. The battery unit 100is made up of battery stacks or modules 102(1) and 102(2) (genericallyreferred to as 102(i) herein) which in turn are made of battery cellcontainers 104 that each house one or more battery cells 106. Theillustrated embodiment includes two rectangular box-like modules 102(i),each of which is made up of six horizontally arranged cell containers104, with each cell container 104 housing one or more battery cells 106.The number of modules 102(i) in the battery unit 100, the number of cellcontainers 104 in each module 102, and the number of battery cells 106in each battery cell container 104 can vary and the orientation andshape of these components can vary as well from application toapplication and accordingly the quantities and orientation in thisdescription are provided as an example of an illustrative embodimentonly.

In at least some example embodiments, battery cells 106 are lithium-ionbattery cells, however other rechargeable battery cells could be used.In some embodiments, battery cells 106 are prismatic lithium-ion batterycells. In other example embodiments, battery cells 106 have cylindricalor other shapes. In the illustrated embodiment, each battery cellcontainer 104 includes a rectangular substantially rigid box-like casehousing one or more battery cells 106. In some embodiments, all of thecell containers 104 within a module 102(i) are substantially identicaland the modules 102(i) that make up a battery unit 100 are substantiallyidentical. In example embodiments, the battery modules 102 (i) may bemounted side by side or one above the other in a support frame or rack108. In some embodiments battery cell container 104 may be non-rigid.

According to example embodiments, a heat exchanger 110 is locatedbetween opposing surfaces 112 and 113 of adjacent battery modules 102(1)and 102(2). The contact surfaces 112 and 113 between the respectivemodules 102(1) and 102(2) and the intermediate heat exchanger 110 maynot be perfectly flat surfaces, and furthermore may be subject todistortion due to expansion and contraction during heating and cooling.By way of example, FIG. 2 illustrates a contact surface 112 defined bythe heat exchanger contacting sides 114 of three adjacent battery cellcontainers 104 in the upper module 102(1). As a result of manufacturingtolerances of the cell containers 104, as well as module assemblytolerances, the cell containers 104 may not be perfectly identical orperfectly aligned. As a result, the heat exchanger contacting sides 114are not aligned, resulting in a heat exchanger contact surface 112 thatis not planer, but rather includes small height transitions at theboundaries between adjacent cell containers 104. As shown in FIG. 2, “T”represents a maximum displacement tolerance between the heat exchangercontacting sides 114 of the cell containers 104 in a module 102. By wayof non-limiting example, tolerance T could for example be in the rangeof 0.5 mm to 1 mm in some applications, however tolerance outside thisrange may also exist in some applications.

Accordingly, a heat exchanger 110 that can maintain consistent contactwith the geometry of the cell containers 104 between adjacent modules102(i) over a range of temperatures and contact surface tolerances andprovide good heat conductivity is desirable in some applications. Inthis regard, example embodiments relate to a heat exchanger structurethat is dimensionally compliant to maintain contact with battery cellscontainers 104 across the battery unit 100 even if the battery cellcontainers do not define a planar heat exchanger contact surface. Insome examples, the dimensionally compliant heat exchanger 110 compressesunder expansion of the first and second battery modules and expand undersubsequent contraction of the first and second battery modules such thatthe heat exchanger structure remains in thermal contact with the batterycell containers 104 throughout a range of normal battery operatingtemperatures.

Referring to FIGS. 3 and 4, in one example embodiment, the heatexchanger 110 is a multi-pass plate-type heat exchanger that defines aninternal serpentine heat exchanger fluid flow passage 118 having a firstend in fluid communication with an inlet fixture 120 and a second end influid communication with an outlet fixture 122. In the illustratedexample, the serpentine fluid flow passage 118 includes multipleserially connected parallel fluid chambers 116(1)-116(6) (genericallyreferred to using reference number 116(i) herein and represented bydashed lines in FIG. 3), with each fluid chamber being joined to asuccessive fluid chamber by a respective substantially U-shaped flowpassage 126. In operation, a heat exchange fluid such as a cooling fluidenters fluid inlet fixture 120, flows through fluid chamber 116(1),through a first U-turn passage 126 into fluid chamber 116(2) and thenthrough a second U-turn passage 126 into fluid chamber 116(3) and so onuntil the fluid flows through the final fluid chamber 116(6) and exitsfrom outlet fixture 122. The heat exchanger fluid travelling throughinternal flow passage 118 could for example be a cooling liquid such aswater or other liquid or gaseous fluid refrigerant for drawing heat awayfrom battery cell containers 104. In some example embodiments, the heatexchanger fluid travelling through internal flow passage 118 could forexample be a heating liquid for heating battery cell containers 104.

As schematically represented in FIG. 1, in one example embodiment eachfluid chamber 116(i) is positioned between a cell container 104 locatedin one module 102(1) and an opposing cell container 104 located in theadjacent module 102(2). In the illustrated example, the heat exchangerincludes six parallel fluid chambers 116(1)-116(6), with each fluidchamber 116 (i) being located between a respective opposing pair ofbattery cell containers 104 in the battery unit 100, however the numberof fluid chambers may be less than or more than six depending on thespecific application. In some example embodiments, the U-shaped regionsthat define U-turn passages 126 are exposed and extend outward beyondthe sides of battery modules 102(1), 102(2) such that the U-turnpassages 126 are not positioned between the battery cell containers 104.In some example embodiments, the U-shaped regions are not exposed andare positioned between the battery modules 102(1), 102(2). The fluidchambers 116(1)-116(6) are each formed within a respective fluid chamberregion 124(1)-124(6) (generically referred to using reference number124(i) herein) of the heat exchanger 110. As will be explained ingreater detail below, in example embodiments, each of the fluid chamberregions 124(i) is individually conformable independently of the otherfluid chamber regions 124(i) of the heat exchanger 110 such thatinter-cell container variances in opposing surfaces 112, 113 between theadjacent modules 102(1) and 102(2) can be accommodated by the heatexchanger 110.

Referring to the sectional views of the heat exchanger 110 shown inFIGS. 5-7, in one example embodiment the body of heat exchanger 110 isformed from six plates that are laminated together, namely first andsecond outer cover plates 128, 130; first and second outer core plates132, 134; and first and second inner core plates 136, 138. In an exampleembodiment, the plates are each formed from roll formed or stampedaluminum or aluminum alloy and are brazed together to form the body ofthe heat exchanger 110. However, the heat exchanger could alternativelybe formed from other resilient metals or materials, including plastics,and other processes.

In an example embodiment, first and second inner core plates 136 and 138are substantially identical, and in this regard FIG. 8 shows aperspective view of an example of an inner core plate 136, 138. Theinner core plate 136, 138 includes a rectangular planar plate portion140 having a raised serpentine boss 142 formed thereon. The serpentineboss 142 conforms to the shape of internal flow passage 118 and includesparallel inner core plate regions 143(1)-143(6) (referred to genericallyby reference 143(i)) that correspond to respective flow chamber regions124(1)-124(6). A serpentine slot 144 is provided along the length of theserpentine boss 142. The slot 144 terminates in enlarged inlet andoutlet openings 146, 148, respectively, at its opposite ends.

In an example embodiment, first and second outer core plates 132 and 134are also substantially identical, and in this regard FIG. 9 shows aperspective view of an example of an outer core plate 132, 134. Theouter core plate 132, 134 is a serpentine member that conforms to theshape of internal flow passage 118. The core plate 123, 134 includesserially connected parallel core plate regions 154(1)-154(6) (referredto generically by reference 154(i)) that correspond to respective flowchamber regions 124(1)-124(6). Adjacent core plate regions 154(i) arejoined by substantially U-shaped portions 156 at alternating ends of theplate 132, 134. The configuration of core plate 132, 134 allows a degreeof physical isolation between each of the core plate regions 154(i) suchthat each of the core plate regions 154(i) can be resiliently compressedindependently of the other core plate regions 154(i). A serpentine slot149 is provided along the core plate 132, 134 and terminates in enlargedinlet and outlet openings 150, 152, respectively, at its opposite ends.

FIG. 10 is a plan view of an example of a substantially planar firstcover plate 128. The first cover plate 128 is also a serpentine memberthat conforms to the shape of internal flow passage 118. The cover plate128 includes serially connected parallel first cover plate regions158(1)-158(6) (referred to generically using reference 158(i)) thatcorrespond to respective flow chamber regions 124(1)-124(6). Adjacentfirst cover plate regions 158(i) are joined by substantially U-shapedportions 160 at alternating ends of the plate 128. The configuration offirst cover plate 128 allows a degree of physical isolation between eachof the first cover plate regions 158(i) such that each of the coverplate regions 158(i) can be displaced towards the center of the headexchanger body independently of the other cover plate regions 158(i).Enlarged inlet and outlet openings 162, 164 are provided a respectiveopposite ends of the serpentine cover plate 128.

FIG. 11 is a plan view of an example of a substantially planar secondcover plate 130. The second cover plate 130 is a serpentine member thatis substantially identical to first cover plate 128 however the secondcover plate does not include inlet and outlet openings 162, 164. Thesame reference numbers are used in the Figures for similar elements incover plates 128 and 130.

Features of the plates 128, 130, 132, 134, 136 and 138 and theirassembly will now be explained in greater detail with reference to thesectional views of FIGS. 6 and 7. In the heat exchanger 110, inner coreplates 136 and 138 are joined face to face with their respective planarplate portions 140 in contact with each other and their respectiveraised boss portions 142 extending away from a centerline C of the heatexchanger body. For explanatory purposes, the term “inner” as usedherein indicates a direction towards the centerline C, and the term“outer” indicates a direction away from the centerline C unless thecontext suggests otherwise. The raised boss portion 142 of the firstinner core plate 136 and the second inner core plate 138 are alignedtogether to partially define the internal serpentine flow passage 118.As seen in FIG. 7, the raised boss portion 142 of each of first andsecond inner core plates 136, 138 is formed by opposing sidewalls 166that extend from the planar plate portion 140 and which each terminateat a planar flange 168 that defines the serpentine slot 144. The planarflanges 168 are substantially parallel to the planar plate portion 140.In an example embodiment, each sidewall 166 has first arcuate wallportion 170 that curves outward relative to the centerline C and asecond arcuate wall portion 172 that curves inward relative to thecenterline C, thereby providing the sidewall 166 with a profile thatgenerally approximates an “S” shape. In some example configurations,such a sidewall profile provides the raised boss 142 with a degree ofresilient conformability such that the boss 142 can be deformed underpressure towards centerline C and then spring back to a normal shapewhen the pressure is removed. The generally S-shaped sidewall profilecan in some example embodiments distribute stress so as to reducefatigue, however other sidewall configurations can alternatively be usedto reduce fatigue.

First outer core plate 132 and second outer core plate 134 are securedon opposite sides of centerline C to the first inner core plate 136 andsecond inner core plate 138, respectively. Each serpentine outer coreplate 132, 134 defines a serpentine channel 174 that opens outwardrelative to the centerline C and forms part of internal serpentine flowpassage 118. In particular the channel 174 is defined by a pair ofopposed sidewalls 176. The sidewalls 176 each extend from an outerplaner peripheral flange 178 to an inner planar flange 180, with theouter flange 178 and the inner flange 180 having substantially parallelopposite facing surfaces. In the illustrated embodiment, each sidewall176 has first arcuate wall portion 182 that curves outward relative tothe centerline C and a second arcuate wall portion 184 that curvesinward relative to the centerline C, thereby providing the sidewall 176with a profile that generally approximates an “S” shape. In one examplethe inner flanges 186 each terminate at an inwardly extending lip 186,with the lip 186 on one flange 180 opposing the lip 186 on the otherflange 180 to define the serpentine slot 149.

The inner flanges 180 of first outer core plate 132 mate with respectiveplanar portions 168 of the first inner core plate 136 to secure thefirst outer core plate 132 to the first inner core plate 136. Asillustrated in FIGS. 6 and 7, the outer core plate serpentine slot 149is aligned with the inner core plate serpentine slot 144, with theopposed lips 186 of the outer core plate extending into the inner coreplate serpentine slot 144. The positioning of the outer core plate lips186 within the inner core plate slot 144 provides a mechanical interlockbetween the inner and outer core plate strengthening the jointtherebetween and also assists in providing a seal against inter plateleakage, and can assist in aligning the plates during assembly of theheat exchanger. In some configurations, the positioning of the outercore plate lips 186 within the inner core plate slot 144 can act as alimit on the extent to which the flow chamber region 124(i) can bedeformed. In some example embodiments other deformation limitingfeatures may be provided in various regions of the body of the heatexchanger to limit deformation of such regions. The second outer coreplate 134 is secured to the second inner core plate 138 in a similarmanner that the first outer core plate 132 is secured to the first innercore plate 136. In some example embodiments the interlock between theinner and outer core plates can be reversed with the lips 186 beingprovided on the inner core plate rather than the outer core plate andthen inserted into the slot 149 on the outer core plate.

In some example embodiments, the generally S-shaped profile of the outercore plate 132, 134 sidewalls 176 provides the outer core plates 132,134 with a degree of resilient conformability such that the outer coreplates can be deformed under pressure towards centerline C and thenspring back to a normal shape when the pressure is removed. Thegenerally S-shaped sidewall profile can in some example embodimentsdistribute stress so as to reduce fatigue; however other sidewallconfigurations can al alternatively be used to reduce fatigue.

In the illustrated embodiment, the serpentine first outer cover plate128 is secured to an outer side of the serpentine first outer core plate132 to seal the first outer core plate channel 174. Each of the coverplate regions 158(i) and U-shaped portions includes a planar centralregion 188 having inwardly directed flanges 190 along the oppositeperipheral edges thereof. Peripheral sections of the planar centralregion 188 mate with the planar outer flanges 178 of the first outercore plate 132, with the outer core plate planar outer flanges 178 beingnested within the inwardly directed flanges 190 of the first outer coverplate 128. The serpentine second outer cover plate 130 is secured in asimilar manner to an outer side of the serpentine second outer coreplate 134 to seal the second outer core plate channel 174. The inwardlydirected flanges 190 may in some embodiments assist in positioning ofthe cover plates during assembly, and can also have a deflection ordeformation limiting effect on the flow chamber regions. In theillustrated embodiment of heat exchanger 110, the inlet openings 146 ofthe inner core plates 136, 138, the inlet openings 150 of the outer coreplates 132, 134 and the inlet opening of the outer cover plate 128 arealigned to form a fluid inlet to the heat exchanger internal flowpassage 118, with inlet fixture 120 secured to the outer cover plate128. Similarly, the outlet openings 148 of the inner core plates 136,138, the outlet openings 152 of the outer core plates 132, 134 and theoutlet opening of the outer cover plate 128 are aligned to form a fluidoutlet to the heat exchanger internal flow passage 118, with outletfixture 122 secured to the outer cover plate 128. The second cover plate130 seals the heat exchanger fluid inlet and fluid outlet on the side ofthe heat exchanger opposite the side to which the inlet and outletfixtures 120, 122 are located. Referring again to FIG. 6, in thepresently described example embodiment, each fluid chamber 116(i) ofeach fluid region 124(i) includes three communicating flow areas, namelythe channel 174 that is defined by first cover plate 128 and first outercore plate 132, the channel 174 that is defined by second cover plate130 and second outer core plate 134, and the central channel 192 that isdefined between inner core plates 136, 138. As a result of slots 144,149, the channels 174, 192 are in fluid communication along the entirelength serpentine flow passage 118.

The planar central regions 188 of the inner and outer cover plates 128,130 provide a physical interface with the battery cell containers 104 ofthe battery unit 100. Thus, in an example embodiment, each fluid chamberregion 124(i) of the heat exchanger 110 has a first cover plate elongateregion 158(i) that engages a respective battery cell container 104 inthe first battery module 102(1) and a second cover plate elongate region158(i) that engages, on the opposite side of the heat exchanger, arespective battery cell container 104 in the second first battery module102(1). In this regard, each fluid chamber region 124(i) of the heatexchanger 110 is secured between and provides heat exchange surfaceswith a pair of opposed battery cell containers 104. As will beappreciated from the above description, the sidewalls 176 of the outercore plates 132, 134 and the sidewalls 166 of the inner core plates 136,138 are configured to provide resilient compressibility of each of theparallel fluid chamber regions 124(i). Furthermore, physical separationby elongate slots 194 (see FIG. 5 for example) between the parallelregions 154(i) of the outer core plates 132, 134 allows the fluidchamber regions 124(i) to each be individually compliant to the physicalseparation between the two battery cell containers 104 that the fluidchamber region 124(i) is located between. The pressure of the heatexchanger fluid within the flow chambers 116(i) can effect thecompressibility of the fluid flow regions 124(i) in some exampleembodiments.

By way of non-limiting examples, in some applications, the plates usedto form the heat exchanger 110 may be formed from H3534 aluminum brazesheet and/or 3003 aluminum. Alternative plate configurations can be usedto achieve similar results—for example, fewer than six plates can beused to form a heat exchanger having individually compliant flowregions.

FIGS. 12-15 show a further example of a heat exchanger 210 that can beused as an alternative to heat exchanger 110 in some applications. Theheat exchanger 210 is similar in function and construction to heatexchanger 110 except for differences that will be apparent from theFigures and the following description. In an example embodiment, theheat exchanger 210 includes a substantially rigid core plate structure228 that is sandwiched between substantially planar first and secondcompliant plate structures 230. In example embodiments, the compliantplate structures 230 are each configured to be resiliently deformablesuch that the heat exchanger 210 is dimensionally compliant to the spacebetween the first battery module 102(1) and the second battery module102(2). The core plate structure 228 of heat exchanger 210 defines aninternal serpentine heat exchanger fluid flow passage 218 having a firstend in fluid communication with an inlet fixture 220 and a second end influid communication with an outlet fixture 222. In the illustratedexample, the serpentine fluid flow passage 218 includes multipleserially connected parallel fluid chambers 216(1)-216(6) (genericallyreferred to using reference number 216(i) herein—see FIG. 15), with eachfluid chamber being joined to a successive fluid chamber by a respectivesubstantially U-shaped flow passage 226. In operation, a heat exchangefluid such as a cooling fluid enters fluid inlet fixture 220, flowsthrough fluid chamber 216(1), through a first U-turn passage 226 intofluid chamber 216(2) and then through a second U-turn passage 226 intofluid chamber 216(3) and so on until the fluid flows through the finalfluid chamber 216(6) and exits from outlet fixture 222.

As with heat exchanger 110, in one example embodiment each fluid chamber216(i) of heat exchanger 210 is positioned between a cell container 104located in one module 102(1) and an opposing cell container 104 locatedin the adjacent module 102(2).

The fluid chambers 216(1)-216(6) are each formed within a respectivefluid chamber region 224(1)-224(6) (generically referred to usingreference number 224(i) herein) of the core plate structure 228 of theheat exchanger 210.

Referring to the sectional views of the heat exchanger 210 shown in FIG.15, the heat exchanger core plate structure 228 is formed from opposedfirst and second core plates 232, 234; and the first and secondcompliant plate structures 230 are each formed from opposed compliantplates 236. In an example embodiment, the plates are each formed fromroll formed or stamped aluminum or aluminum alloy and are brazedtogether to form the body of the heat exchanger 210. However, the heatexchanger could alternatively be formed from other resilient metals ormaterials, including plastics, and other processes.

In an example embodiment, first and second core plates 232 and 234 aresubstantially identical, and in this regard FIGS. 16 and 17 show planviews of examples of core plate 234 and 232, respectively. The coreplates 234 and 232 each include a rectangular planar plate portion 240having a raised serpentine boss 242 formed thereon. The serpentine boss242 conforms to the shape of internal flow passage 218 and includesparallel core plate regions 243(1)-243(6) (referred to generically byreference 243(i)) that correspond to respective flow chamber regions224(1)-224(6). A difference between first core plate 232 and second coreplate 234 is that inlet and outlet openings 246, 248, are formedrespectively, at the opposite ends of the raised boss 242 of first coreplate 232.

In an example embodiment, first and second compliant plates 236 thatform the compliant plate structures 230 are substantially identical, andin this regard FIGS. 19 and 20 show an example of a compliant plate 236.In the illustrated example, compliant plate 236 is a rectangular platethat includes a plurality of raised parallel, elongate bosses 250 thatare separated by slots 252 that extend through the plate. FIG. 21 is anenlarged partial sectional view showing two compliant plates 236opposingly mated to form a compliant plate structure 230. As seen inFIG. 21, each of the elongate bosses 250 includes a planar central wallthat is bordered by sidewalls 256 which each terminate at a peripheralplaner flange 258. The flanges 258 from one compliant plate 236 matewith the flanges 258 from the opposing compliant plate 236 to formcompliant plate structure 230. As seen in FIG. 21, the opposed bosses250 from the mated compliant plates 236 define internal chambers 260such that the mated compliant plates 236 define a plurality of parallel,elongate compliant chamber regions 262(1)-262(12) (generically referredto as 262(i) herein). In one example embodiment, chambers 260 are sealedchambers that are filled with a fluid or gas such as air or filled witha non-fluid thermal gasket. In another example embodiment, chambers 260may be vented. In the illustrated embodiment, the compliant platestructure 230 includes twelve elongate compliant regions 262(i), two foreach of the six flow chamber regions 224 (i) of the core plate structure228.

In an example embodiment, the compliant regions 262(i) of the compliantplate structure 230 are each individually deformable such that each ofthe compliant regions 262(i) can be individually compressed up to athreshold amount under external pressure and then rebound back to itsoriginal shape when the pressure is removed.

In some example embodiments, the compliant plates 236 are formed fromthinner material than the core plates 232, 234 with the result that thecore plate structure 228 is relatively rigid compared to the compliantplate structures 230 that it is sandwiched between. By way of nonlimiting example, compliant plates 236 could be from aluminum having athickness of 0.2 mm and the core plates 232, 234 formed from aluminumhaving a thickness of 0.6 mm, however many alternative thicknesses couldbe used.

Turning again to FIGS. 15-18, in the heat exchanger 210, first andsecond core plates 232, 234 are joined face to face with theirrespective planar plate portions 240 in contact with each other andtheir respective raised boss portions 242 extending away from each otherto define the internal multi-pass serpentine heat exchanger fluid flowpassage 218. Compliant plate structures 230 are provided on the oppositefaces of the core plate structure 228 to provide an interface with thefirst battery module 102(1) and the second battery module 102(2),respectively. In the illustrated embodiment, one each side of the coreplate structure 228, a pair of parallel elongate compliant chambers262(i), 262(i+1) extend the length of each fluid chamber region 224(i).The compliant chambers 262(i) and 262(i+1) that are located on oppositesides of each fluid chamber region 224(i) permits each of the fluidchamber regions to be individually compliant to physical separationbetween the two battery cell containers 104 that the fluid chamberregion 124(i) is located between.

Accordingly, in the embodiments of FIGS. 1 to 21, a heat exchanger 110,210 is placed between two battery modules 102(1) and 102(2) that eachinclude a plurality of battery cell containers. In some applications,the surfaces of the battery modules 12(1) and 102(2) that contact theopposite sides of the heat exchanger 110, 120 may not be perfectly flatdue to a lack of perfect alignment of the battery cell containers thatmake up the battery modules 102(1) and 102(2). Thus, in at least someexample embodiments, to help maintain contact between the battery modulesurfaces and the opposite sides of the heat exchanger 110, 210, the heatexchanger 110, 120 includes independently conformable regions that eachhave a spring effect such that each conformable region coincides with arespective pair of opposed battery cell containers and can adaptivelyflex under the compressive forces applied at the region. Accordingly, inat least some embodiments, when assembling a battery unit that includesbattery modules 102(1), 102(2) and heat exchanger 110, 120, acompressive action or step occurs during which regions of the heatexchanger 110 undergo a degree of compression to facilitate good thermalcontact between the battery modules 102(1), 102(2) and the heatexchanger 110, 120.

In some example embodiments the conformal heat exchanger configurationsdescribed above could be used between fuel cell modules in place ofbattery cell modules. Accordingly, the heat exchanger structuresdescribed herein can be used in a power producing unit that comprises afirst module comprising a plurality of power producing cells such asbattery cells or fuel cells and a second module comprising a pluralityof power producing cells such as battery cells or fuel cells, the heatexchanger structure being disposed between opposing surfaces of thefirst stack and the second stack and defining one or a plurality offluid flow passages, the heat exchanger structure being dimensionallycompliant to accommodate different separation distances between opposingcells within the battery unit, and in some example embodiments,dimensionally compliant to compress under expansion of the first andsecond stacks and expand under subsequent contraction of the first andsecond stacks. In some example embodiments, an intermediate material orstructure may be placed between the outer cover plates and the batterycell containers 104 to enhance thermal conduction and account forirregularity in the surface profiles of the individual battery cellcontainers.

In example embodiments, the conformal heat exchanger 110 described aboveincludes compliant regions over substantially the entire fluid flow pathdefined by the heat exchanger. In some example embodiments, thecompliancy of the heat exchanger may be more localized. In this regard,FIGS. 22-25 illustrate a battery unit 300 that incorporates a heatexchanger 302 having localized compliant regions according to furtherexample embodiments, as will be explained in greater detail below. Thebattery heat exchanger 302 includes multiple (N) substantially identicalspaced apart heat exchanger modules or plates 306(1) to 306(N)(generically referred herein using reference number 306) that aresubstantially aligned in a row or column. The battery unit 300 includesbattery modules 304(1) to 304(N−1) (generically referred to usingreference number 304) that are interleaved with the heat exchangerplates 306(1) such that at least one battery module 304 is locatedbetween and in thermal contact with the opposing surfaces of twoadjacent heat exchanger plates 306.

FIG. 25 schematically illustrates three heat exchanger plates 306(1),306(2) and 306(3) of heat exchanger 302 and FIG. 24 schematicallyillustrates a battery module 304 which could for example be locatedbetween heat exchanger plates 306(1) and 306(2) or between heatexchanger plates 306(2) and 306(3). In the illustrated embodiments, theheat exchanger plates 306 and the battery modules 304 have a rectangularfootprint or profile; however they could have other shapes in otherexample embodiments such as square or circular. Each battery module 304houses at least one battery cell which may for example be a prismaticlithium-ion battery cell (however other rechargeable battery cells couldbe used). In the illustrated embodiment, each battery module 304includes a rectangular substantially rigid case or frame housing the oneor more battery cells.

As seen in FIGS. 23 and 25, in an example embodiment, the heat exchangerplates 306 each define multiple internal fluid flow paths or passages308 (shown in dashed lines in FIG. 25) between a fluid inlet 310 and afluid outlet 312. In the illustrated embodiment, each plate 306 includeseveral substantially parallel C-shaped internal flow passages 308,however many different fluid flow path configurations are possibleincluding for example a single serpentine flow path between the inlet310 and outlet 312. In an example embodiment, the fluid inlet 310 of allthe plates 306 are connected to a common fluid inlet manifold 314, andthe fluid outlets 312 are all connected to a common fluid outletmanifold 316. In operation a heat exchange fluid is distributed to eachof the heat exchanger plates 306 via inlet manifold 314 and collectedfrom the heat exchanger plates 306 via outlet manifold 316. In someexample embodiments, the fluid passing through the internal flowpassages 308 is used to cool the heat exchanger plates 306 and thebattery modules 304 located therebetween, although in some exampleembodiments the fluid passing through the internal flow passages 308 isused to heat the heat exchanger plates 306 and the battery modules 304during at least some parts of battery operation.

In an example embodiment, each heat exchanger plate 306 is formed from apair of mating, substantially identical first and second plate members318, 320 as best seen in FIGS. 22 and 23. In the illustrated embodimentfirst plate member 318 and second plate member 320 are eachsubstantially planar members having outer facing grooves 322 thatcooperate to define internal fluid flow passages 308. Furthermore, theplate members 318, 320 each include a pair of outwardly extendingbubbles or bosses 324 and 326 that each define a respective flow opening328. The bosses 324 of the first and second plate members 318, 320 ofeach heat exchanger plate 306 are aligned to form the plate inlet 310,and the bosses 324 of all the plates 306 are aligned in fluidcommunication with each other to form inlet fluid manifold 314 of theheat exchanger 302. Similarly, the bosses 326 of the first and secondplate members 318, 320 or each heat exchanger plate 306 are aligned toform the plate outlet 310, and the bosses 326 of all the plates 306 arealigned in fluid communication with each other to form the outlet fluidmanifold 316 for the heat exchanger 302.

In example embodiments, the first and second plate members 318, 320 areformed from braze clad aluminum alloy or stainless steel or other metalsheet material, however plastic or other synthetic materials could beused in some embodiments. Bosses 324, 326 may for example be formed bydeep drawing portions of the metal sheet material. In some exampleembodiments, the area a sheet material where bosses 324, 326 are to beformed may be formed with thicker material in order to provide materialfor deep drawing of the bosses. For example, a tailor made patch couldbe applied in the area of the bosses before forming the plates.

In some example embodiments, the heat exchanger 302 is pre-assembled asa unit, brazed together, and then the battery modules 304 insertedbetween the heat exchanger plates 306. In the illustrated embodiment,the inlet and outlet manifolds 314, 316 are both located on the sameside of the heat exchanger 302 to facilitate lateral insertion of thebattery modules 304 from the opposite side of the heat exchanger 302.

According to example embodiments, the bosses 324, 326 are compliant sothat they can be axially compressed after the battery modules 304 areinserted to achieve thermal contact between the battery modules 304 andthe heat exchanger plates 306. Such a configuration may in someapplications permits a pre-compression spacing that facilitatesinsertion of the battery modules 304 during assembly while providingtight thermal contact between the heat exchanger plates 306 and thebattery modules 304 post-compression. Additionally, in someconfigurations the compliant nature of the bosses 324, 326 may allow themanifolds 314, 316 of the heat exchanger 302 to effectively expand andcontract during battery operation in response to expansion andcontraction forces applied by the battery modules 304 as they heat upand cool down, facilitating good thermal contact between the heatexchanger plates 308 and the battery modules 304 across a range ofoperating temperatures.

Thus, referring to FIG. 23, the bubble or boss height “H” of a boss 326has a pre-assembly height before the battery modules 304 are inserted ofH=X, and a post assembly height of H=Y, where Y<X; during assembly,after the battery modules 305 have been inserted, the heat exchanger 302is compressed to collapse the boss heights down to H=Y. In theembodiment of FIG. 23, each annular boss is formed from an axiallyextending first annular wall 330 that terminates at a radially extendingfirst annular shoulder 332, which in turn terminates at a second axiallyextending second annular wall 334, which in turn terminates at aradially extending second annular shoulder 336 that defines opening 328.The shoulder 332 forms a cantilever member that provides compliancy inthe boss 326 such that the elastic nature of the boss 326 is largely afunction of the width or diameter D of the first annular shoulder andthe thickness and resiliency of the material forming the boss 326. Inone example embodiment, the boss 326 has substantially linear forcedeflection curve as displaced between H−X and H=Y. Inlet boss 324 issubstantially identical to outlet boss 326.

In another example embodiment, the boss 326 is configured to provide a“snap through” effect whereby it is biased to H=X for a certain range ofaxial compression, then biased to H<=Y once the degree of axialcompression passes a threshold. In this regard, FIG. 26 illustrates at(A) a boss 324, 326 biased in a pre-assembly position (before insertionof battery modules) where H=X, and at (B) the same boss 324, 326 biasedin a “pack” or post-assembly position (after insertion of batterymodules 304 into the heat exchanger 302) where H<=Y<X. In boss 324, 326,once the angle of deflection of the shoulder 332 passes a threshold, theboss “snaps through” to its post assembly position. In some examples,once the threshold deflection is reached the bosses of the opposedplates 306 bias the plates towards an inter-plate separation that isless than battery module height such that the plates 306 effectivelyclamp the opposite surfaces of battery module 304 to retain thermalcontact with the battery module through a range of normal operatingtemperatures for the battery unit 300. As illustrated in FIG. 26 at (C)in some embodiments, the compliance of bosses 324, 326 is dependent onthe shoulder dimension L and the thickness of the material used to formthe plates.

As shown in FIG. 26 at (D), in some example embodiments a bellows likestructure 325 can be formed on the bosses 324, 326 of either or bothcore plates in order to provide the bosses 324, 326 with a degree ofresilient compressibility. Again, the amount of compliance is dependenton dimension L and the thickness of the material used to form theplates.

Accordingly, the compressible bosses 324, 326 of the heat exchanger 302provide localized compliance in the region of the heat exchangermanifolds.

According to another example embodiment, a further battery unit 400 andheat exchanger 402 configuration will now be explained with reference toFIGS. 27-31. The battery unit 400 and heat exchanger 402 of FIGS. 27-31is similar in construction and function to the battery unit 300 and heatexchanger 302 of FIGS. 22-26 except for differences that will beapparent from the Figures and the present description. In particular, aswill be explained in greater detail below, rather than use compressiblemanifold bosses to achieve localized compliancy, the heat exchanger 402relies on flexible manifold panels to facilitate substantially parallelcompression of the heat exchanger after insertion of the battery modules304 in order to provide good thermal contact between the heat exchangerplates and the battery modules.

The battery heat exchanger 402 includes a stack of multiple (N)substantially identical spaced apart heat exchanger modules or plates406(1) to 406(N) (generically referred herein using reference number406) that are substantially aligned parallel to each other in a row orcolumn. The battery unit 400 includes battery modules 304(1) to 304(N−1)(generically referred to using reference number 304) that areinterleaved with the heat exchanger plates 406 such that at least onebattery module 304 is located between and in thermal contact with theopposing surfaces of two adjacent heat exchanger plates 406.

FIGS. 27, 30 and 31 schematically illustrate four heat exchanger plates406(1)-406(4) of heat exchanger 402. In the illustrated embodiments, theheat exchanger plates 406 and the battery modules 304 have a rectangularfootprint or profile; however they could have other shapes in otherexample embodiments such as square or circular. As with battery unit300, each battery module 304 in battery unit 400 houses at least onebattery cell which may for example be a prismatic lithium-ion batterycell (however other rechargeable battery cells could be used). In theillustrated embodiment, each battery module 304 includes a rectangularsubstantially rigid case or frame housing the one or more battery cells.

As seen in FIGS. 29 to 31, in an example embodiment, the heat exchangerplates 406 each include a main plate section 434 that defines one ormore internal fluid flow paths or passages 408 (shown in dashed lines inFIG. 29) between a fluid inlet region or panel 410 and a fluid outletregion or panel 412. By way of example each main plate section 434 mayinclude several substantially parallel C-shaped internal flow passages408, however many different fluid flow path configurations are possibleincluding for example a single serpentine flow path through the mainplate section 434 between the inlet panel 410 and outlet panel 412. Asbest seen in FIGS. 29 and 30, the inlet panel 410 defines an internalinlet fluid passage 430 that is in fluid communication with the mainplate internal passage 408, and the outlet panel 412 defines an internaloutlet fluid passage 432 that is also in fluid communication with themain plate internal passage 408. The inlet panel 410 includes a pair ofaligned inlet openings 428I in fluid communication with the inlet fluidpassage 430 and the outlet panel similarly includes a pair of alignedoutlet openings 428O in fluid communication with the outlet fluidpassage 432. In the illustrated embodiments, the inlet and outlet panels410, 412 are generally rectangular in shape, however they could havedifferent shapes in different embodiments.

As can be seen in FIGS. 27, 28 and 29, the inlet panel 410 extendssubstantially parallel to and spaced apart from an end of the main platesection 434, but is attached by a joining portion 440 to the main platemember such that a gap 436 partially separates the inlet panel 410 fromthe main plate section 434. The joining portion 440 defines an internalfluid passage between inlet panel passage 430 and the main plateinternal passage 408. Similarly, the outlet panel 412 extendssubstantially parallel to and spaced apart from the same end of the mainplate section 434, but is attached by a joining portion 442 to the mainplate section 434 such that a gap 438 partially separates the outletpanel 412 from the main plate section 434. The gap 438 also extends toseparate the inlet panel 410 from the outlet panel 412. The joiningportion 442 defines an internal fluid passage between the main plateinternal passage 408 and the outlet panel passage 412.

In example embodiments, although the heat exchanger plate 406 has agenerally rigid structure, the joining portions 440 and 442 allow theinlet panel 410 and outlet panel 412, respectively, to flexindependently of each other relative to the main plate section 434.

In an example embodiment, the fluid inlet panels 410 of all the plates406 are connected in a stack with inlet openings 428I in axial alignmentto form a common fluid inlet manifold 414, and the fluid outlet panels412 are all connected in a stack with outlet openings 428O in axialalignment to form a common fluid outlet manifold 416. In operation aheat exchange fluid is distributed to each of the heat exchanger plates406 via inlet manifold 414 and collected from the heat exchanger plates406 via outlet manifold 416. In some example embodiments, the fluidpassing through the internal flow passages 408 is used to cool the heatexchanger plates 406 and the battery modules 304 located therebetween,although in some example embodiments the fluid passing through theinternal flow passages 408 is used to heat the heat exchanger plates 406and the battery modules 304 during at least some parts of batteryoperation.

In an example embodiment, each heat exchanger plate 406 is formed from apair of mating, substantially identical first and second plate members418, 420 as best seen in FIGS. 30 and 31, first plate and second platemembers being mirror images of each other. In the illustrated embodimentfirst plate member 418 and second plate member 420 are eachsubstantially planar members having outer facing grooves 422 thatcooperate to define internal fluid flow passages 408. The plate members418, 420 each include an outwardly extending bubble or boss 424 on theportion thereof that forms the inlet panel 410 and an outwardlyextending bubble or boss 426 on the portion thereof that forms theoutlet panel 412, with the inlet panel boss 424 defining inlet opening428I and the outlet panel boss 426 defining outlet opening 428O. Theinlet panel bosses 424 of the first and second plate members 418, 420 ofeach heat exchanger plate 406 are aligned, and the inlet panel bosses424 of all the plates 406 are aligned in fluid communication with eachother to form inlet fluid manifold 414 of the heat exchanger 402.Similarly, the outlet panel bosses 426 of the first and second platemembers 418, 420 of each heat exchanger plate 406 are aligned, andoutlet panel bosses 426 of all the plates 406 are aligned in fluidcommunication with each other to form the outlet fluid manifold 416 forthe heat exchanger 402.

In example embodiments, the first and second plate members 418, 420 areformed from braze clad aluminum alloy or stainless steel or other metalsheet material, however plastic or other synthetic materials could beused in some embodiments.

In some example embodiments, the heat exchanger 402 is pre-assembled asa unit as shown in FIG. 27 and brazed together. Subsequently, thebattery modules 304 inserted between the heat exchanger plates 406 toform a completed battery unit 402. In the illustrated embodiment, theinlet and outlet manifolds 414, 416 are both located on the same side ofthe heat exchanger 402 to facilitate lateral insertion of the batterymodules 304 from the opposite side of the heat exchanger 402.

As noted above, the presence of gaps 436 and 438 between the inlet andoutlet panels 410 and 412, respectively, permit the panels 410, 412 ofeach heat exchanger plate 406 to flex relative to main battery platesection 43, and vice versa. Once the heat exchanger 402 is preassembled(before battery modules 304 are inserted), the inlet panels 410 arerigidly connected in a stack with bosses 424 aligned to form the inletmanifold 414, and the outlet panels 412 are rigidly connected in a stackwith bosses 426 aligned to form the outlet manifold 416. The flexibleconnection between each of the panels 410, 412 and their respective mainheat exchanger section 434 permits the main heat exchanger sections 434to have a pre-compression spacing that facilitates insertion of thebattery modules 304 and a post compression spacing that provides a goodthermal contact between the plates and the battery modules 304. Forexample, as shown in FIG. 31, the heat exchanger 402 haspost-compression inter-plate separation of H—in some exampleembodiments, during battery module 304 insertion the main plate sections434 are separated from each other a distance greater then H, after whichthe plate sections 434 are compressed in a substantially parallel mannerto separation distance H to achieve thermal contact between the batterymodules 304 and the heat exchanger plates 406. Such a configuration mayin some applications facilitate insertion of the battery modules 304during assembly while provided tight thermal contact between the heatexchanger plates 406 and the battery modules 304 post-assembly. Inexample embodiments, post compression the heat exchanger is biased tohave an inter-plate separation of H or less than H so that the batterymodules 304 are effectively clamped between pairs of opposed heatexchanger plates 406.

Accordingly, the heat exchanger 402 makes use of local compliance in theregion of the heat exchanger manifolds to facilitate thermal contactwith inserted battery modules 304.

In some example embodiments, intermediate tubular connectors (examplesof which are described in greater detail below in the context of FIGS.32A, 32B) other than or in addition to bosses 424, 426 may be employedto interconnect inlet panel and outlet panel sections 410, 412.

As shown in the embodiment of FIGS. 27 and 29 of heat exchanger 400, theflexible panels 410 and 412 are located at the same end of the heatexchanger 400 with joining portion 440 located near a midpoint at thecommon end and joining portion 442 located near a side edge. Themanifold 416 connecting the panels 412 is spaced apart from the joiningportion 442 and located near the midpoint at the end of the heatexchanger 400, and the manifold 414 connecting the panels 410 is spacedapart from joining portion 440 and located near the opposite side edge(e.g. the opposite side that the joining portion 442 is located at).Such a configuration, in which one of the inlet/outlet openings428I/428O (and resulting manifold) is near a midpoint at one end of theof the heat exchanger 402 and the other of the inlet/outlet openings428I/428O (and resulting manifold) is at the corner near the same end ofthe heat exchanger 402, can in some applications facilitate parallelcompression of the heat exchanger plates 406 to facilitate post-assemblythermal contact between the heat exchanger plates and the batterymodules. However, in some example embodiments the panels 410, 412 couldhave different relative locations, and in this regard FIGS. 29A, 29B and29C each illustrate different possible locations of inlet and outletpanels 410, 412 relative to the main heat exchanger plate sections 434in heat exchanger embodiments 402-1, 402-2, and 402-3, respectively. Theheat exchangers 402-1, 402-2 and 402-3 are substantially identical inconstruction and operation to heat exchanger 402, with the onlysubstantial difference being in the location of the flexible panelsrelative to the main heat exchanger section in the heat exchangerplates.

Referring again to the compliant boss heat exchanger 302 of FIGS. 22-26,in at least some example embodiments an intermediate manifold connectoris used between adjacent heat exchanger plates 306. In this regard,FIGS. 32A and 32B are each enlarged partial sectional views (taken froma similar view as FIG. 23) that illustrate further example embodimentsof a heat exchanger that includes manifold connectors between compliantboss regions of adjacent heat exchanger plates 306. The heat exchangersof FIGS. 32A and 32B are substantially identical to the heat exchanger302 of FIGS. 22-26 except for differences that will be apparent from theFigures and the present description. As shown in FIG. 32A, rather thanhaving direct contact between the bosses 326 of adjacent heat exchangerplates 306 (shown as 306(2) and 306(3) in FIG. 32A), the opposing bosses326 of adjacent plates 306(2) and 306(3) are spaced apart from eachother and interconnected by an intermediate cylindrical connector 340that forms part of the manifold 316. In the embodiment of FIG. 32A, theannular wall section 334 of the boss 326 of each opposing plate member318 and 320 of adjacent heat exchanger plates 306(2), 306(3) isinternally received within and connected to an inner surface of thecylindrical connector 340. The inlet bosses 324 are similarly connectedby intermediate cylindrical connectors 340. In the embodiment of FIG.32A, the bosses 324 and 326 are deformably compliant as described abovein respect of the embodiments of FIGS. 22-26 to allow interleaving ofand post assembly thermal contact with battery modules 304. Theembodiment of FIG. 32B is similar to that of FIG. 32A, except that thecylindrical connector 340 is inserted into (rather than over) theopposed annular walls 334 of adjacent bosses 326.

In example embodiments, the annular walls 334 and cylindrical connector340 are connected by brazing and may include a mechanical interlock suchas a swaging or staking mechanical connection to facilitate pre-brazingassembly and strengthen the post-brazing connection. In some exampleembodiments, the use of an intermediate connector 340 facilitatesseparate pre-assembly and testing of each of the heat exchanger plates306, followed by pre-assembly of the heat exchanger as a complete unitthat is then ready for final assembly by the interleaving of batterymodules 304 within the heat exchanger structure. The intermediateconnector 340 could also be used with flexible panel heat exchangers402, 402-1, 402-2 and 402-3 of FIGS. 27-31.

FIGS. 33-35 illustrate yet a further compliant heat exchanger 302′ foruse in battery unit 300 according to another example embodiment. Theheat exchanger 302′ is similar in construction and operation to the heatexchanger 302 of FIGS. 22-26 and the heat exchangers of FIGS. 32A and32B with the exception of differences that will be apparent from theFigures and the present description. Similar to the heat exchangers ofFIGS. 32A and 32B, the heat exchanger 302′ of FIGS. 33-35 makes use ofan intermediate manifold connector 350 for interconnecting adjacent heatexchanger plates 306. However, the heat exchanger 302′ differs from theheat exchanger 302 of FIGS. 22-26 and the heat exchangers of FIGS. 32Aand 32B in that inter-heat exchanger plate compliancy is achieved byhaving a two-piece compressible intermediate manifold connector 350rather than by building compliancy into the bosses on the plate members320, 318. In this regard, as shown in FIG. 33, in at least someembodiments the plate members 318 and 320 of heat exchanger 302′ do notinclude raised boss regions around the flow openings 328 (or flowopenings 326). Although the figures illustrate a manifold connector 350as applied to the outlet manifold 316, the inlet manifold 314 of heatexchanger 302′ is constructed in a similar manner.

An example of a two-piece compressible intermediate manifold connector350 will now be described with reference to FIGS. 33-35. Terms usedherein that denote absolute orientation such as upper and lower, rightand left are used for the purpose of description only with reference tothe orientation of the Figures and not to limit the configurationsdescribed herein to any absolute physical orientation. In an exampleembodiment, each intermediate manifold connector 350 defines an internalheat exchanger fluid flow passage 364 for transporting a heat exchangerfluid to or from heat exchanger plates 306, and includes first andsecond resilient, compressible manifold fixtures 352 and 354. As shownin FIGS. 33 and 35, in an example embodiment, the first fixture 352includes an axially extending lower or first annular wall 357 that has alower end connected within the outlet opening 328 of the upper platemember 320 of heat exchanger plate 306(3). The first fixture 352 alsoincludes an axially extending upper or second annular wall 360 thatmates with the lower end of the second fixture 354 at a joint 356. Thesecond annular wall 360 has a larger diameter than the first annularwall 357 and the lower end of the second annular wall 360 and the upperend of the first annular wall 357 are joined by an integral, generallyradially extending annular shoulder 358.

Similarly, the second fixture 354 includes an axially extending upper orfirst annular wall 357 that has an upper end connected within the outletopening 328 of the lower plate member 318 of heat exchanger plate306(2). The second fixture 354 also includes an axially extending loweror second annular wall 360 that mates with the upper end of the firstfixture 352 at a joint 356. The second annular wall 360 has a largerdiameter than the first annular wall 357 and the lower end of the secondannular wall 360 and the upper end of the first annular wall 357 arejoined by an integral, generally radially extending annular shoulder358.

In an example embodiment, the first and second fixtures 352, 354 areeach formed from single piece of metal material (for example aluminum,aluminum allow or stainless steel) that is deep drawn to provide theshape shown in the Figures. In one example embodiment, the metal isthinner in the shoulders 358 of the first and second fixtures 352, 354than the first annular wall 357, providing each of the first and secondfixtures 352, 354 with a degree of resilient crush-ability orcompressibility as illustrated by dashed lines 362 and 363 in FIGS. 33and 34, with dashed lines 362 representing a post-compression locationof the shoulders 358 and lines 363 representing a post-compressionlocation of the heat exchanger plates 306(2) and 306(3).

In one example embodiment, each heat exchanger plate 306 ispre-assembled with a pair of first fixtures 352 connected to its upperplate member 320 (one at outlet opening 328 and one at inlet opening326), and a pair of second fixtures 354 connected to its lower platemember 318 (one at outlet opening 328 and one at inlet opening 326).Each pre-assembled heat exchanger plate 306 is brazed, and the brazedplate 306 then be tested for leaks if desired. The heat exchanger plates306(1)-306(N) are then assembled in a stack to form a completedpreassembled heat exchanger 302′, and the joints 356 between matingfixtures 352, 354 are brazed. The preassembled heat exchanger 302′ hasan inter-plate separation distance of H1 as shown in FIG. 33, allowingbattery modules 304 (which have a height less than H1) to be interleavedbetween the heat exchanger plates 306. After the battery modules 304 areinserted, the heat exchanger 302′ is compressed to height H2 as shown inFIG. 33 such that the battery modules 304 are in thermal contact onopposite sides with the heat exchanger plates 306 they are eachsandwiched between.

As explained above in respect of FIG. 26, in at least some exampleembodiments the first and second fittings 352, 354 are configured tobehave with a snap-through effect such that through an initial range ofdeflection the fittings 352, 354 are biased towards the position shownin solid lines in FIGS. 33 and 34 (which corresponds to inter-plateseparation H1), but after a threshold level of deflection the fittings352, 354 then become biased towards the position indicated by dashedlines 362 (which corresponds to inter-plate separation H2). In someexamples, once the threshold deflection is reached the fittings 352, 354bias opposed plates 306 to an inter-plate separation that is less thanthe actual post assembly separation distance H2 such that the plates 306effectively clamp the opposite surfaces of battery module 304 to retainthermal contact with the battery module through a range of normaloperating temperatures for the battery unit 300.

FIG. 34 illustrates at (B) an example of a possible mechanical jointthat can be applied between the first and second fittings 352, 354 atjoint 356, and at (A) possible mechanical joints between the firstsecond fittings 352, 354 and the respective plates 306. As shown at (B)in one example, the lower end of the second fitting 354 is receivedwithin the upper end of the first fitting 352, forming an overlap joint.As shown at (A), in some examples, an axial flange 364 may be providedaround opening 328 to provide an overlap joint between the plate and thefirst or second fitting 352, 354. As shown in FIG. 35, in some exampleembodiments, a rib 366 may be formed on the first annular wall 357 offittings 352, 354 to mate with the plate 306 about opening 328, and insome example the end 368 of a fitting 352, 354 that is inserted into theopening may be expanded or swaged or staked to provide a mechanicaljoint with the plate pre-brazing.

FIGS. 36A, 36B and 36C are views of a further embodiment of a fitting ofa two-piece compliant manifold connector that can be applied to the heatexchanger of FIG. 33, with FIG. 36A being a top view, FIG. 36B being asectional view taken along lines A-A of FIG. 36A and FIG. 36C being aperspective view. The fitting 370 is substantially identical to firstand second fittings 352, 354, with the exception that the radiallyextending shoulder 358 of the fitting 370 has an arcuate profile thatprovides a weakened region at the transition between the annular wallsof the fitting 370 that can in some embodiments reduce the compressiveforce required to move the fitting 370 to its compressed or crushedposition.

FIG. 37 is a sectional view of yet a further embodiment of a two-piececompliant manifold connector 380 that can be applied to the heatexchanger of FIG. 33. The manifold connector 380 includes two fittings382 and 384 and is similar to connector 350 except that the fittings 382and 385 are each reversed such that the larger diameter region of eachfitting is joined to a respective plate 306, and the smaller diameterregions of the fittings are connected together, providing the connector380 with an hourglass type figure as opposed to the bulging middle ofconnector 350.

Although the heat exchanger manifolds 314, 316, 414, 416 have beendescribed above as either dedicated inlet or outlet manifolds withparallel heat exchanger fluid flow occurring in the same directionthrough all heat exchanger plates 306, 406, it will be appreciated thatflow circuiting could be used to route the heat exchanger fluid throughmanifolds 314, 316, 414, 416 in a variety of different pathconfigurations by including flow barriers along the respective lengthsof one or both of the manifolds.

Accordingly, in the embodiments of FIG. 22-37, the battery units areformed from battery modules that are interleaved with heat exchangerplates. In at least some examples, the battery modules are inserted intoa pre-assembled heat exchanger, with the spacing between the heatexchanger plates being dimensioned to accommodate battery modules withinacceptable tolerance ranges. After insertion of the battery modules, acompression action or step on the heat exchanger ensures good contactbetween the heat exchanger plates and the battery modules. In at leastsome example embodiments, the compressible manifold configuration of theembodiments of FIGS. 22-26 and 32A-37 and the flexible inlet/outletplate configuration of FIGS. 27-31 provide compliance to absorb thecompressive forces in a substantially parallel movement of the platepairs with rather limited angular movement of the plates in order toreduce the risk of buckling.

A common feature of the embodiments of FIGS. 1-37 is the provision ofgood thermal contact between battery modules and the heat exchangermodules after assembly, with the thermal contact being facilitated byresilient compliance of regions of the respective heat exchangerstructures. In at least some example embodiments, compliant regions ofthe heat exchangers of FIGS. 1-37 are at least temporarily displaced asportions of the heat exchangers are positioned between battery modules.

The various embodiments presented above are merely examples and are inno way meant to limit the scope of this disclosure. Variations of theinnovations described herein will be apparent to persons of ordinaryskill in the art, such variations being within the intended scope of thepresent disclosure. In particular, features from one or more of theabove-described embodiments may be selected to create alternativeembodiments comprised of a sub-combination of features which may not beexplicitly described above. In addition, features from one or more ofthe above-described embodiments may be selected and combined to createalternative embodiments comprised of a combination of features which maynot be explicitly described above. Features suitable for suchcombinations and sub-combinations would be readily apparent to personsskilled in the art upon review of the present disclosure as a whole. Thesubject matter described herein and in the recited claims intends tocover and embrace all suitable changes in technology.

What is claimed is:
 1. A heat exchanger for use with at least twobattery modules, each of the battery modules comprising at least onebattery cell housed within a rigid container, the heat exchangercomprising: a plurality of planar heat exchanger plates that eachinclude: a main plate section defining an internal fluid passage, aninlet panel connecting an inlet to the main plate section, and an outletpanel connecting an outlet to the main plate section, wherein the inletpanel and the outlet panel are joined to the main plate section, each ofthe inlet panel and the outlet panel joined to the main plate sectionvia a joining bridge, and a gap separating each of the inlet panel andthe outlet panel from the main plate section such that the main platesection can be displaced relative to each of the inlet panel and theoutlet panel via the respective joining bridge, the inlet panel and theoutlet panel of at least some of the heat exchanger plates being joinedto the inlet panel and the outlet panel of adjacent heat exchangerplates to form a stack of spaced apart, substantially parallel, heatexchanger plates, the main plate sections of the stacked heat exchangerplates being compressed together to engage battery modules insertedtherebetween.
 2. The heat exchanger of claim 1, wherein the main platesections are compressible towards each other to provide thermal contactwith battery modules inserted between the heat exchanger plates.
 3. Theheat exchanger of claim 2, wherein the inlet panel and the outlet panelare located at a common side of the heat exchanger stack defining abattery module insertion side of the heat exchanger that is opposite tothe common side of the inlet panel and the outlet panel.
 4. The heatexchanger of claim 2, wherein the inlet panel and the outlet panel arelocated at opposite sides of the heat exchanger stack.
 5. The heatexchanger of claim 2, wherein each heat exchanger plate comprises afirst plate and a second plate secured together and defining the fluidflow passage therebetween.
 6. The heat exchanger of claim 5, wherein thefirst plate and the second plate are formed from metal material andbrazed together.